Protective device for electrical circuits.



H. VAN DEVENTER.

PROTECTIVE DEVICE FOR ELECTRICAL CIRCUITS.

APPLICATION FILED NOV. 5, 1909.

Patented Aug. 26, 1913.

[[VVE/VTOR.

lV/TNESSES:

HARRY B. VAN DEVENTEB, 0F SUM'IER, OUTE. CAIEQULZHA PROTECTIVE DEVICE FOR, ELECTRICAL CIERGUIT$3 Specification of Letters Patent.

Fatenteol Aug. 26), twi

Application filed November 5, 1909. Serial E0, 526,371.

To all whom'z't may concern:

Be it known that I, HARRY R. VAN Dn- VEN'TER, a citizen of the United States, residing at Sumter, county of Sumter, State of South Carolina, have invented certain new and useful Improvements in Protective. Devices 'for Electrical Circuits; and Idohereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use same.

The invention is designed more particularly for use as a lightning arrester for protecting electrical circuits and their connected instruments from. the injurious efiects of overcharges of atmospheric electricity or other high potential currents.

The object of the invention is to secure a device of the utmost efliciency, that may be readily and cheaply constructed, and in which the perishable parts are interchange able and easily replaced.

My invention is illustrated in the -accompanying drawings wherein- T Figure 1 is a longitudinal section of the instrument through the center thereof. Fig. 2, a front elevation of the conductive member showing shape before forming. Fig. 3, is a front elevation of the complete instrument.- Fig. i, a cross section of the'conductive member, the support therefor and the grounding medium. Fig. 5, a cross sect-ion of the complete instrument showing the assembly of the various parts.

The same reference figures apply to the same parts of the drawings throughout.

My invention consists in the peculiar formation of the conductive member of the arrester. Also its method of association with the other parts, and particularly relates to that class of arresters wherein a conduc-- tive memberv in the form of a coil-or winding having continuous turns offers an irregular path of high impedance to the current, which is thereby forced to jump a gap to a suitable grounding medium located adjacent to the coil.

My improved conductive member obviates the necessity of accurately forming the coils heretofore used, while retaining the feature of impedance, which is further increased by making the angles of the conductor as abrupt as possible, and providing points at said angles, which aid the current in jumping to an adjacent grounding mediam.

increased efiiciency.

suitable conductive material such as sheet iron or-zinc. While the form as shown in the figure is preferred it will be understood that any form having abrupt bends forming a zig zag path from one end to the other may be used. it is also quite obvious that this may be constructed from wire, or a metallic ribbon. After being formed, the piece is bent so that the points of same are disposed at an angle to its longest dimension as will be noted by reference to the figures, in which the conductive member 21 is shown bent around the block 3, which serves as a support. By this means, a conductive path is formedfrom terminal 19 to terminal 20 having many abrupt angles, and the current must pass successively through each bend, and through points 17, 16, 15, 14,

13 and the corresponding points on the other side of the piece.

This path offers a great choking effect to any form of high tension current alternating in character, andthe progress of same is thereby impeded. his the points of piece 21 are in close proximity to a grounding medium shown at 2, being separated therefrom only by small air gaps, indicated at 22 and 23, the current jumps the gaps from the piece 21 to the grounding medium in preference to overcoming the impedance of the angles, and is thereby removed from the circuit.

It is evident that While the sharp pbints on the conductive member 21 facilitate the discharge of foreign currents from same to the grounding medium, they are not strictly necessary, but are advisable as they secure It will be noted that the distance between the points and the grounding medium is easily determined by the thickness of the support 3 which also j eliminates mica or other insulating material often used to insure a proper separation of these parts.

The points may become damaged, or sufficient particles of the grounding medium become loosened to form a short circuit between the conductive member and the ground, and to facilitate the removal of the conductive member from the device, 1" use block 3, which supports the conductive member 21, the ends 19 and 20, of which are held by the spring numbers 4 and 5, which are in turn held by binding posts 6 and '2' provided with nuts 8, 9, l0, and 11 for holding the circuit wires. litnvill he seen that block 3 carrying. the conductive member 21 is removable as a unit from the complete instrument, without disturbing the circuit connections, and without the use .of tools. This, makes the conductive member interchangeable. Should it become necessary to remove the grounding medium from the device, it is accomplished by removing screw 12 and lifting the grounding medium 2 out of the recess in the block 1.. A suitable terminal 27 is provided for the grounding medium. this being equipped with nuts 25 and 26 for clamping the ground wire. The terminal 27 is connected to the grounding medium by means of screw 12 and piece 18, which is brought up and over the outer edge of block 1, and is provided at. the top with a screw 24, sothat two of the complete devices can be placed'side byside with the two screws 24 in proximity to each other, and these may be connected by a short piece of wire so that one ground connection will serve for .a metallic circuit.

.The preferred method of connecting my device is to bring the incoming line wire to po'stfi, the wire from the instrument to post 7;, connecting the remaining side of the instrument and post 27 to the ground. This Cpl-aces the conductive member 21 in series with the lncoming line, and forelgn currents must traverse the numerous angles 1n piece 2las previously described. It is also 3 obvious that thedevice may be used by connecting 27 to theground, the incoming line to post-6, and then continuing the incoming line from p'ostfi to the instrument, the other side of the'instrument being grounded. In

' this event,,the conductive member 21 issimply a branchor side path, and is notin series with thevinstrulnentto be protected, but the device is still eflicient as an arrester owing to. the many sharp points in close proxlmity I to the groundin medium, this favoringthe. escape of; any oreign current of suflicient to ump the small fair gap. propotential vided.

" lVhileiIliave shown 'only one form of base,

conduction-grounding medium, and assem- {-bly, it willbe understood that various other '.formsfandfmethods of assemblycan be used "without departing from the essential fea- "tures of my invention.

I am aware that it is not new in a device ofthis character to use a conductor having fabrupt turns or angles 1n combination with a grounding medium adjacent thereto, but I do claim thatit is'newto have this conductor form abrupt turns or angles without being in coiled form, and to provide same with-teeth. v

Therefore, what I claim to be new in a protective device for electrical circuits is,

1. An arrester comprising in combination conducting member having portions bent into a plurality of planes, some of said bent tion a conducting member having portions disposed in three planes, some of said portions having a, saw-tooth contour, an insulating block for supporting said member, a grounded memberdisposed in proximity to said saw-tooth portions, a base for said grounded member, terminals on said base and means for removably connecting said conducting member to said base and terminals.

4. An arrester comprising in combination a conducting member having portions bent into three planes, some of said portions having a saw-tooth contour, a plate disposed adjacent to the pointed ends of said sawtooth portions, means for supporting said memberand plate, terminals for said member and plate, resilient means for keeping saidmeans removably secured to one another and for connecting said member to its terminals. I

5. A lightning arrester comprising in combination a member formed from flat material andbent into a zigzag shape, having relatively sharp angular portions, said member having its end portions bent, a support for said member, means for securing said member to saidsupport, a base for said support, means'for securing said support to said base, and making electrical contact with said member, a plate disposed on the upper portion of said base arranged to come within sparking distance of said bent portions of said member and means for grounding said plate. a

6. A lightning arrester comprising in combination a conducting member formed from a single strip of material bent into zigzag shape and having its angular and end portions bent downwardly, a support for said member arranged to hold said member on its uppergsurface and to permit the bent portions .to extend down. the sides of the same, a base of insulating'material having holes and recesses therein, springs disposed on and secured to the end portionsof said base and arranged to movablyreceive said support, a conducting member to make electrical contact with the latter, means for securing said springs to said base arranged for connecting circuit wires thereto, a rechaving means connected thereto whereby the same can be grounded or connected in a series with other arresters.

7. A lightning arrester comprising in combination a conducting member formed from a single strip of flat material into a zigzag shape and having its angular and end portions, bent downwardly at right angles to the inner portions, a support forsaid member made of insulating material and arranged to hold said member on its upper surface and to permit the bent portions of the same to extend downwardly on the sides of the support, a base of insulating material having holes and recesses therein, spring plates disposed in opposite end portions of said base bolts for securing said plates to said base disposed in the holes of the same, nuts disposed on said bolts for securing cir-, cuit wires thereto, a plate disposed in one of the recesses in the upper portion of said base and arranged to extend beyond the sides of said support and the same is pressed in between said spring plates and held securely thereby to said base, the end portions of said member being bent so as to beheld between said -support and spring plates so the current will be conducted thereto when the arrester is placed in a circuit, said .plate being arranged to come within spark- ;ing distance of said bent angular portions,

means connected to said plate whereby the same can be grounded or several ofsaid arresters put in a series. 7

8. A conductive member inclosing three sides of a rectangular block and forming angles along the sides of same, means for sup- 7 porting the conductor and block on a base, and a grounding medium adjacent theconductor.

In testimony whereof I hereunto aflix my signature in the presence of two witnesses.

HARRY R. VAN DEVENTER, Witnesses:

M. O. DELGAR, LIZZIE DINKINS. 

